SOUTHERN CALIFORNIA / A news summary

Son, 49, Held in Death of 89-Year-Old Mother

FOUNTAIN VALLEY — An 89-year-old Fountain Valley woman died after being struck by her son and left semiconscious on a kitchen floor flooded with cold water, police said Thursday.

Officials said they are still not sure exactly what caused the death of Chinh Thi Nguyen, who died at UC Irvine Medical Center. Police took her 49-year-old son, Long Thanh Nguyen, into custody for a 72-hour psychiatric evaluation. He has not yet been charged.

Fountain Valley Police Sgt. Jim Perry said the son struck his mother Wednesday during an argument. Police believe that the mother was sitting in a kitchen chair when her son punched her in the face. Officers say the victim fell backward in her chair and hit her head against the tile floor, lapsing into semiconsciousness.

As she lay on the floor, a toilet in a nearby bathroom overflowed for unknown reasons and flooded the kitchen floor, where the woman remained helpless until another son returned home, police said. Paramedics arrived at the two-story home in the upscale neighborhood around 6:10 p.m. Wednesday, Perry said. Nguyen was taken to the medical center, where she died of an apparent heart attack around 11:20 p.m.